<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .container {
            width: 300px;
            height: 300px;
            margin: 100px auto;
            border: 5px #09f solid;
            position: relative;
        }

        .computer,
        .code {
            position: absolute;
            top: 0;
            right: 0;
            background-color: green;
            width: 30px;
            height: 30px;
            line-height: 30px;
            text-align: center;
        }
        .computer{
            background-color: orange;
        }
        .computer img,
        .code img {
            width: 20px;
            height: 20px;
        }
        .white{
            width: 42.43px;
            height: 42.43px;
            background-color: #fff;
            position: absolute;
            top: 9px;
            right: 9px;
            transform: rotate(45deg);
        }
    </style>
</head>

<body>
    <div class="container">
        <div class="login">
            <input type="text"><br>
            <input type="text"><br>
            <button>登录</button>
        </div>
        <div class="saoma">
            <img src="./img/code.png" alt="">
        </div>
        <div class="computer"><img src="./img/computer.png" alt=""></div>
        <div class="code"><img src="./img/code.png" alt=""></div>
        <div class="white"></div>
    </div>
    <script type="text/javascript">
        let computer = document.getElementsByClassName('computer')[0]
        let code = document.getElementsByClassName('code')[0]
        let login = document.getElementsByClassName('login')[0]
        let saoma = document.getElementsByClassName('saoma')[0]
        saoma.style.display = 'none'
        computer.onclick = function () {
            computer.style.display = 'none'
            code.style.display = 'block'
            login.style.display = 'block'
            saoma.style.display = 'none'
        }
        code.onclick = function () {
            computer.style.display = 'block'
            code.style.display = 'none'
            login.style.display = 'none'
            saoma.style.display = 'block'
        }
    </script>
</body>

</html>